Research On Servaral Methods Of Engineering Structure Reliability Analysis

Because of its unique practical value and good mechanical property,Civil engineering structures have been applied to the infrastructure construction of people from all walks of life.But because of many uncertain factors,there is the possibility of structural failure.The structure is not absolutely safe.Simple mechanical calculation can not solve practical problems.In order to ensure the normal operation of the structure in the specified time and conditions,the reliability analysis of the structure becomes more and more important.As a quantitative index to judge the reliability of the structure,the reliability of the structure can describe the reliability quantitatively.Various forms of uncertainty can be considered in some form.It is not an easy task to solve the multiple integral of the structural failure probability directly,so it is necessary to use the approximate method to calculate the structure reliability.The key of structure reliability analysis method is how to analyze uncertainty and build structure performance function,then to find the corresponding solving method for the reliability.When the result is not up to the standard,it is necessary to redesign the structure and risk assessment.In this regard,this paper has the relevant research literature at home and abroad.Based on the idea of optimization theory,this paper use constrained nonlinear optimization method and model fitting method to deeply research the analysis method of engineering structure reliability.As a supplement to the conventional analysis method,it plays a vital role in the development of this field.Under the condition of explicit structure performance function,aiming at the deficiency of the too large feasible region,the paper puts forward one dimensional analysis method of structure reliability based on the original research.According to the geometric meaning of reliability index,from the selection of iterative direction,the reliability analysis method of HL-RF based on modifiing with adaptive iterative direction,accelerates the speed of iteration algorithm and avoids the misconvergence problem.The correctness and effectiveness of the iterative algorithm are verified by numerical examples and comparison.Through the analysis of decision theory,the paper proposes a reliable structure optimization model of utility decision analysis method with the utility function and fuzzy preference relation,calculates the reliability of the nonlinear explicit structure performance function,and uses examples to verify the correctness and effectiveness of the method.Under the implicit structure performance function and the guidance of optimization theory,based on the condition of support vector machine and rough set theory,the structural reliability analysis method of RST-SVM is maked,and analyzes the uncertainty with rough set theory.The rationality of the method is verified through examples and experimental method.Based on the rough set theory,this paper establishes the quantitative form for the relevant attributes of the structure and discusses the influence degree to the structural reliability.Based on the structural dynamic reliability,a large amount of time varying macro measurement information is analyzed in detail.The introduction of Weibull theory model is for structural dynamic reliability analysis.According the condition of deformation and time to judge and feedback,it discusses the causes of the danger.On this basis,the paper analyse structural reliability.Through the engineering example,the reliability of slope for deformation failure mode is discussed,and the practicability of the model is verified.The results show that the method is reasonable.The reference value of the project is compared with the numerical results.